SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd839794e760bbc3f72b048d58fbe723e9f6e169be643862e3b1c736ce71a2b27' 
  AND token = 'KKnHCHUJKbTj6KMKvUvp0dw1MVftJ4Pgey4wXDs8s9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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