SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e4b93c7f7786927e074387323aaecd323d0276d6d262e101f0ff3055b3e8ce3' 
  AND token = 'tIGbICqfpIKBhOntWNpzuSfZINQGJT+YJbkDkePHVpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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