SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4376b6ec2fe19b404a256a140acf504ec1ea5d987f7f2e8f95ad99a147d13ee7' 
  AND token = 'IJADmg/oGqoTFLuQtQY002eqrVCzWVViaDH2e1LKN3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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