SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce1044b9b5cc365c28e8eb5cfd42b0b6b7b860ef4e883c134f5dfb118d1604f4' 
  AND token = 'nkQFZgnHU9zCGjwk1S5M/FJaGGfOMRRhlzE5EQpbSF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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