SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c64a404d5306caddb509dff1b22f09bf5505f182e5d4f61641b7dce8b3fb3701' 
  AND token = '4mw/oQYVorKplTsX1UQUdBnn+8pD7NKWNzSJNrMKQBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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