SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b48ca913cfe0cfdd2cb02391a80d4c8303decb283a79393ef5e6c8708bea417' 
  AND token = 'Yoju5V0BcspiWJXwf2qrXqd62lPasNlgSje0XJpeRoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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