SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20e734627527230cde74bcac722f68a1ec9daf67df1d5368bbc773ff97bd0391' 
  AND token = 'ZYIImeMHppQMo1RSOUoJOXIvEl9zf2eBkexO1xBp+fQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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