SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e44d583417331b7599989349118b063b74660070bc72344c1d4967dca34bf6c4' 
  AND token = 'ZoaRwexo2ZpXFgxtZPl+sbcXCDLAAnmouZhPD5q/4eA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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