SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13e97c208f300d454b134d2fb2558a6ece8a9a400e3017d5f9be0dddc7c548c9' 
  AND token = 'ZuMb+qo1B/LfqWIKLuujMu2X0/ufaePH99/cjAwkqHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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