SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '870a9a60aa10b082656bc569f3e4d9ca5d8ecc39b1c144db3e17d7395a625c87' 
  AND token = 'X3+dBuz70rD/4Im6R/Kj/MnjhfOjF58fyo+ix9RYvZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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