SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd98d4f810f7c3c1ee63b8158fa70634b33c15535fbb028538de835b6c1a5a894' 
  AND token = 'MR+DgC/TB6lh884JpmAVKrT9+u/9mxG7ZozpV25MEF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}