SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60e16539f17325007d7acf254b01db3f2867f43fdc1fa6329029937c90ea71e5' 
  AND token = '6CgeoaUKj7fYb2sJjMWYxfGf/qlbpR7FuppGr/6c+Bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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