SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ea0767c17005e65d41898b71d55125a04c4bfc9d3afa22ef3f21311640b25b5' 
  AND token = 'mit8uUilhnVOCnZRaQphtbZNOcf/cDCPyoweDq9RMw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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