SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a7529b3921b052e284a262c536da6cde492d99438aefd07435ab9996c46187f' 
  AND token = 'NI4quR7H85HewnmFrG8ZAFzkwSoaPMTk9uuNxShEGCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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