SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '891051a167f4b9a80d11c9afa403cf7589fe4196e26a2051039b1351814ff2ed' 
  AND token = 'czntwsJ2+G0GLk/xMta9tfrVGA0GlHywINwhmdAS5uQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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