SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e2a790bf6bbcd5d05b80828be084fe251489cb78bd41812d135edce1dac52cdb' 
  AND token = 'sCzITR8YoNyGrBQpnr4JsrqJPvw02cPFSlsQz0oBPig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}