SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8dadfe736664bba5d2056bd6c74942fd982b6773e1c1dccd3225a5397cd13d8' 
  AND token = 'UaH49VdkahKIyECXWXWdJEEOUANxRCwlrh4XtM/kmCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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