SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd1402433ecab9de2287c82a63a3ae40284cebcc088108caa7599ac700918ce7' 
  AND token = '1runI2ZIUdnOi05/mirxI2DlUhm4+nMrzF3EfbvGfN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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