SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4470b202a2acc6fe311735c88133580650cb846cc255517074b7d494758d62b8' 
  AND token = 'mjXEzigv+U00sxqUezIdN5s3lyWFIsnd1AJCwqzAt1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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