SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df89374f497e288e4da5e1bc748398830ab6647115f5ef60f7a54ddcb3e66119' 
  AND token = '1758C9md3ZqgwgT+qlL9wXH3xNvGNDcSJtIn+v5bBMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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