SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f2fe192108fe5f0b6bdf555e94bdccca2d8b32aa323ed348eacafd5bda4ff414' 
  AND token = 'bMzMdBTy7RRfc12LVRhALVIGFB0MAnfBz3/5fIYao24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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