SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8dea5b8cddc72a8b8c891bf7828a6897ae3128f7ff5d9868d07d27ed18c4e79' 
  AND token = 'vemFx6pssE3KMJHkBW3ruIgk4LKpvddbfCWTU4aY9tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}