SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '716427bfb7b237959e72c364ff53a16782540fa09d64a8dee204e3803a2b9f94' 
  AND token = 'b9iC6s4ebRq4g3jl1UFrZyoKbppsUZmajDwivJbhd5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}