SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42b3db9c42f60ecd4f575be515a65d31684074a4dd799248ff22040c1a574d37' 
  AND token = 'fwVuIB3o7FsSPqzJV+2EQQLFuwTKXdY24ZOF6glb2ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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