SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12e8523e16cfcd9ba6516df4fc79dc72f0eeeae3df3db54b5b1645f98d431a26' 
  AND token = 'GSvQrcJmsGdMWM2dOTeITpR85ropPssW5gc2CuxbdKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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