SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9b6812d7b0b75cbb10ce8fd33207e8f44d88785532306268a2f4a7f0b009ad5' 
  AND token = 'R6C0QNHPa31DnikNVGnbMv0mDZnMkXDi42AxICYC1nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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