SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dff81e0c6336621b424ca7dff02b837b582f24c79e5c7a407bf8b4a1477700f4' 
  AND token = 'bopiKj9m++/KvUPiDKCUxGAkopwdzznR1LBqrWFcAzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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