SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd4fa47e8bde8334baf3fa65ca87d98c6abdc5fbff2bbd8111c4b486172a4d55' 
  AND token = '5kPLCsilmDNWCiwv/l7GmC5cvaT2s1EbmPAAtLP951o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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