SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fac2970a28ecf4310e0201bae95fe60877eb56def2628f6c4504c568013c245' 
  AND token = 'PhoGF9TWRAKVwNCqvI3HJNQGfqtx/IakFErQkzS/Zj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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