SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66faf7463294fb47a7a4a3c7fda559543089938830b1ec0b64a0cd4eef377e6a' 
  AND token = 'oeTotOwCcvjP6dxuT7xnfdK1WuWPPon8fMWmeg9Qoiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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