SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70ba33423f77f674e55dda63b3a115b074dc597dbd8e1a8786c2ee32ea75746c' 
  AND token = 'xfYsBVzgAZLtWRnw1gC/6c7JnW6NeYVCKgGqTR3zUKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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