SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cdb1e80517c60f6fbc5b1b84ccf7679d5a663c77080bcf54d092263f1375952' 
  AND token = 'KJ6DpE8oG92Y1XBkHCp0jG+rnkxNQYik/HmFKWqq1SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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