SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb390bd2be06fe5143da730e9a4f8c070c08ae80bcb7f8472060c0efee020cd1' 
  AND token = 'p2q1Odaxfa7QiZrs8QToPi+QcLYavFCVHmCs6Cpw+kM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}