SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e4ba93a7e67d4b162b9922bc00053d62d5e26a23ef6d88358832ebcc0206401' 
  AND token = 'XCKTnSfvZt5IBfq/JLpagmlVtosBNFXIJZlYZGla4Pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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