SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7aa5ee867e368593c206a66f04f34e64d2d8c14087b27473d276fcebd541a381' 
  AND token = 'umcZlr5ItXzrVy/KlQk9cEVQCriH471vXVDJaTSZoJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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