SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fda35c77e53017356695739828624cf815612f6c7963c4b787c1324ce2cb69f2' 
  AND token = '0TpKPwxli5hlgK5C/mtsGGaWgo7quGSEZ/1+njg0Eak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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