SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1f5680d5068efd28168af51630e2e061b09f8096c873a025836404c6f15a3fb' 
  AND token = 'S0bchJPG63GL1y5jeaFsUpGbbmCSwiAAoTHGyItUeLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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