SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e966019ce2ad31ffbe3c96eda1c8606d1185c6089b82562f527b05123372d748' 
  AND token = 'qXcinvzrVmRziLII+Ahgzhnb/p7y4PNN7OSfh+sRBRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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