SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93068c9b007081df652414d13d2986341020dfbfdc4541af3563e7a9eefaafe6' 
  AND token = 'GLsKocEIKIxRihAeV8QqRnTltPBDm/YcUc+vQEvIl3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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