SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91479327503398fd33464b462d75b465c34c024100e34759489c5692c177d200' 
  AND token = 'KjDZmoTmFhVuOIWA1IheReqJN+yYEs/fFftNlxnDd30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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