SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e54b50c0113ad2059cafd559cbfcc9c00714ffebaab841b72928e115fbbfbf2' 
  AND token = 'Z3OCoFrJWhGrbzwDUdVUm8nukjM0tB3RmUFa6O/5oj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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