SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df0d420f7c7131c5cb6a574401481e6d96723558747938f81cabcb75ecb9b4b1' 
  AND token = 'Qv6+/Q3Nn7iey+TLzRVMyXpOCFR5TdmdGLzYEjtbQnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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