SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bb53cdc7a1980bfb8d49208f246074aa955d688917de07a95e14fcc7b2ffc89' 
  AND token = 'uV6JgRjZbDfJb5oHBI/b+LxmwJaPsyXKneEgmoyn7tg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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