SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d14f3d12311283e266f579e73953d36d152291d52c694ba1cb0bd5fcb2bf0b2' 
  AND token = 'YElF0BevY/+qJuGT8DGVOI3jodBiEGnlKfOjU1fBisA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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