SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd558e6ea9cb91c8664c5ecd37bff21edad2045e84ca226721e3ca211c18bad04' 
  AND token = 'UxoTvpbi+FW6GTpSogAKp7xYiYfUrCUnprmlZpv02bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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