SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fb5925e6f7f065ece31eb52632e5b3eb35cd3d2eb16ef8dab5a3e8fab112c3c' 
  AND token = 'XQQLIe8i4s5qjDsLshb6BBdThgdJxcPCVvguzhxex2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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