SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d10337034603d9ef29027b3975167005c95f0133d84e05a79a0a4dd394e422b' 
  AND token = 'Vu+WZoUFWYxBGvcAYensGL1HPP2qSwft6NbsfAdw/oE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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