SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c914308a09cb43dd307ef87aa06c45faf9a6c50eee888581439b2828f49c7a6' 
  AND token = 'wKyARQAuQB20OZSJOYP60aqhm9sXl3CG8WO9l/0k3cU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00126

JSON explain

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