SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f814b8e092897dcc41090efe6cff0bf98a69f3e0c669302de8c728693c0c046' 
  AND token = '2gegPWloPMJtrC3SmKjdXxXkUkr49ssTJVm2aUOtxn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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