SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bc8580f82fc0a9e66564370b1474e392161e7e4ffade2f3191735bec31d8eb3' 
  AND token = '48hNZM1bn0Kd/HSs7/P5U7hOXO7prFyjbSdrHMEOV2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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