SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '784fafa1160f6c7229855395a233daa6d277931fb68127241c51d5a3dc3240d1' 
  AND token = 'KnPCAxg376EjKqDGE4v9zuhmwnH0Tcv0OUK4Eil/LvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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