SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '766cd5f5d2389459a93f787b339308adbd1fdb80d42f873249a962d43b2e6ab4' 
  AND token = 'oxsyPgwKgCeDTrmvrWBFWVxeiJUguc3u4OBYDWMF+kU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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