SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ff8e4e6bb749296fd587c623669d0bab35261f5d9f8fb0afa1cd495bb196daf' 
  AND token = 'TLjeKINHt/pMvxnzv9ubZJFOi4l5zOMBmfcSg6IFPcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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