SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ffc79fb10a0159de0981ba04a1292fd324bbd16f36bf75c243ceaeee1f77633' 
  AND token = 'fXmIR5djurZHZ8yhPawevrItYwAHpI8+7ztjfMsj1O4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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