SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc6597f9d1658c76e9ddc9ed451be2feab978724469427581cc0e8a1be88d33' 
  AND token = 'GNl7CMMDrE8Cs/bthkbNO9dCY/XJErvKBUKtsFeUwNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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