SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04a4cce11e5532582f235110c9f8aba7ea074b209858c71bcd4521770ff70e7' 
  AND token = 'JYqtGqfzkN/WQdS77ene97S3nWehIdd8Smmk+z/8aTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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