SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ee33d684d78e7226426d9afae3b31ba814dbe7438515a78dfc25659acbce9359' 
  AND token = 'SxdJiZQO/sCDGaIYCJTbR5v+hssQQFoD9rU59aKk7OI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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