SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aef34a3531aa4a0de510b6a4fe2f45d4d6225c4991a13227f80fba7bdc288f4' 
  AND token = 'SmMi7/13QrH+VuBT+VGr0z5Bw/kvHXlOJsFz5T90GOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}