SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aed3d88b501a651da5c363f5ff50c3a07270a13a7be542907091b19de389545f' 
  AND token = '/Svx+KjO3D6YJpJkFZsOATiBqdUpKP1zydXUQTIisuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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