SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a23a935a0609a24ca0557939c1727eae51997969da41dc2dbed24bee9bee3dc4' 
  AND token = 'Ww2cMTFU8Ft1khppYu+c5vZO2BSPHs5rpMslG0J+1e8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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