SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '125d0874bc8b70a676a13e43647ada2dcbb43d4eb79d8e9159e70281a5f611a4' 
  AND token = 'uNGgOAyhsPeFz+Jda5ETaHYp6kzJygpwbZepClFNA1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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