SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f228b800bc0013662258e3f36710a881c5f306349f779f8304f22cbb1dc136c' 
  AND token = 'eCW3DArMHcUfUPwdW8EBnn+qJf+BEhgc7pDPmxV+/+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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