SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e6098db2cda03f3fda1de5bb861fb64f8c01db521a423d60bfd4ba40dce9069' 
  AND token = 'sBeWBy+KKBESnxiqA8kVxNg4LFNim0ZEtyNrzhmA7uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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