SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '462fc29cc9c18019e9328da8cb6de3d128cd9f15e570bcab59529243880c16e0' 
  AND token = 'ZUdKZZCmucjZdAnyRh8Cj6qJY0r2eMcaOYT4/jvZkag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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