SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7221473ed7f01d815281a99b183a77fc1650cba9aee0df40f56e98ce863ba53b' 
  AND token = 'drexXD3MvyIbDVVLLw41Rcz1zcwv3p+eKWk7xvo7/K0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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