SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d2124f3e477bc631e412c45cc5231f64444772d8935f3bef0b9f8984cbc3b54' 
  AND token = 'U7U3QzNF88rUGqpEVtTJ0qp1fA/S0404bE5pJ+7auY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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