SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16afd25c085edb5f50fa4235d61775c227238135689c766e7659ef76e6c763aa' 
  AND token = 'NkMqDKszb5XK8Mcj7yl5DlqTVZokERhU+KQ1i02KVSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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