SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc6234224285d441122a4ad976f6691c99e39d201a386a888fdfb3aea7561926' 
  AND token = 'dbd2DV47YRRZPHmQ6Zfcvv5VpcszvhPfnfbLc28wFGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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