SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e272fbf56d2f2790f9308343b953c549b9b60627498524ed74130e0f970ca7d7' 
  AND token = 'TVEtp3FvVJXeL2BwOSeQ/sN+kyKR8xG1y98c3++knJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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