SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6ba5e0ce8512e316bcd139fbfd261df869fb76dd5b25a7c1799f75f4495b46a' 
  AND token = 'FqmrPe5Di+BQNLPt06yZSwTG/OTvf/XpsIAoDSfU4g8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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